Question

If sin(a+b)=sinacosb+cosasinb, then find the value of sin 75°

Answer 1

sin75=sin(45+30)
sin(a+b)=Sina cosb + cosa sinb
sin(45+30)=sin45cos30 +cos45sin30
=1/√2(√3/2) +1/√2(1/2)
=√3/2√2 + 1/2√2
=√3+1/2√2

Answer 2

Step-by-step explanation:

sin 75 = sin(30+45)=sin30.cos45+cos30.sin45

                               =1/(2*2^1/2)}+3^1/2*1/2*2^1/2}

                               =(1+3^1/2)/2